The popularization of cloud computing has led to a need for higher speed for communication, while the distance between communication apparatuses that engage in data transmission and reception is becoming longer due to factors such as business globalization. When communication is performed using a system such as Transmission Control Protocol (TCP) in which a packet lost during communication is retransmitted, the communication apparatus at the transmitting side decides the size of data to be transmitted next, and whether or not to perform the retransmission, using a confirmation acknowledgment packet from the communication apparatus at the receiving side. The Round Trip Time (RTT) in the route between the communication apparatus at the transmitting side and the communication apparatus at the receiving side becomes longer when the distance between the communication apparatus at the transmitting side and the communication apparatus at the receiving side is longer. For this reason, in communication that uses TCP, the communication speed becomes slower when the distance between the communication apparatus at the transmitting side and the communication apparatus at the receiving side becomes longer. Meanwhile, in the communication system that uses error correction, the communication apparatus at the transmitting side transmits a redundant packet in addition to the packet that includes data to be transmitted. When a packet loss occurs, the communication apparatus at the receiving side recovers data included in the lost packet using the redundant packet. For this reason, in the communication that uses error correction, while it is possible to avoid delay due to retransmission, there is a problem wherein the throughput is reduced because of the transmission of the redundant packet.
As a related art, a communication apparatus has been proposed that measures the jitter generated in the communication that uses the redundant packet and the jitter generated in the communication that uses the system in which the lost packet is retransmitted, and that transmits data using the communication system in which the jitter is smaller. Furthermore, a method has also been proposed in which the error correction mechanism is decided using a state parameter and a connection parameter. Here, a state parameter is quality information such as the bandwidth, the allowable delay time and the like that is required according to the application in which the data are used. Meanwhile, a connection parameter is information related to the communication connection.
Patent Document 1: International Publication Pamphlet No. WO2007/061087
Patent Document 2: Japanese National Publication of International Patent Application No. 2002-507369
The system in which the packet lost during communication is retransmitted has a problem in which, when the distance between the communication apparatus at the transmitting side and the communication apparatus at the receiving side becomes long, the communication speed falls due to an increase in the Round Trip Time. Meanwhile, the method in which the redundant packet used for error correction is transmitted has a problem in which the throughput is reduced because of the transmission of the redundant packet, while it is possible to avoid deterioration in the communication speed due to the retransmission process.
In the communication apparatus that performs communication while adopting the system in which the jitter is smaller among available systems, although the variation of the time needed for transmission of the respective packets may be reduced, it is impossible to increase the speed of the communication. In addition, in the system in which the error correction mechanism is decided using a state parameter and the like, the communication system is decided using quality information required by the application. For this reason, there is a problem in which, when the quality information is unknown, it is impossible to appropriately select the communication system. Therefore, the method in which the communication system is decided using quality information is not applicable to the communication apparatus that forwards data to be used in unspecified applications.